I've been shooting a D300/Subal rig for about 9 months now. It's great, but it has me wanting more (full frame). I was thinking that the D700 doesn't seem like enough of a jump to justify the cost of a new housing (Subal ain't cheap!) and out comes the Canon 5DM2. Now, I love what it has to offer but am not sure if I'm willing to switch brands, because my gf shoots Nikon as well, and frankly, I like Nikon (never had a Canon DSLR though). If only I knew what Nikon has in store to compete with the new Canon and when this will be available. Should I make the switch and risk switching back again, or just keep shooting the D300 and wait for Nikon to release an upgrade to the D700? Anyone know what the Nikon product cycles are like, and how long this wait might be? I figure that at least I can start collecting FF Nikon lenses in the meanwhile, shooting them on land with the D300.

Aaaargh, the pace of innovation is both so sweet and also so frustrating when you just get settled in with a rig!

Personally, I think that the D300 is a better all rounder as an underwater camera than the D700 (depending on the type of photography you do) so I can understand you not wanting to upgrade/downgrade. The D700 does have better IQ than the D300 (a la DXO labs), but in underwater you have to search long and hard to spot the difference. The D300 has better AF frame coverage and takes cool DX lenses like the sigma 17-70mm and the Tokina 10-17mm, plus as the recent rectilinear corner sharpness tests showed its works easily with wide rectilinears.

That said it is pretty easy to make a D300 fit a D700 housing - alas it is not always so simple the other way around.

I actually don't have the Sigma 17-70, so I might give that a try (I've been shooting the 10-17 and 105 macro so far). Either of you have a chance to put your hands on the 5DM2 yet? Like I said, looks like an amazing camera but I have so much invested and love my Nikon.

I have a 5DmkII and it's an amazing camera. But I wouldn't advise you to switch. What is it that your D300 is not doing for you that you absolutely have to have? Will you be shooting at ISO1600, or do you need to shoot HD video?

The D300 has better AF frame coverage and takes cool DX lenses like the sigma 17-70mm and the Tokina 10-17mm, plus as the recent rectilinear corner sharpness tests showed its works easily with wide rectilinears. Alex

I'll post some pics in a few days when I have a faster download; but the Tokina 10-17 with 1.4 TC worked splendidly this last week on the D700.

Here is the list of current Sigma lenses. Yes, there are two 17-70 lenses. Both are macro, one is HSM and the other is not. The HSM version is bulkier and does not fit all port systems. There is also a version with more limited zoom range (18-50) but with faster f/2.8 constant aperture. It also comes in two variants.